Add lazy_object_proxy spkg

[embray]

Adds the lazy_object_proxy package for Python as a dependency of sage.

This could be used to replace code in sage.misc.lazy_import. It's also a slightly more generic implementation of a lazy proxy (granted, the existing one in Sage could also be made more generic with only slight modifications).

More details about how I intend to use are in #22793.

Upstream tarball: https://pypi.python.org/packages/65/63/b6061968b0f3c7c52887456dfccbd07bec2303296911757d8c1cc228afe6/lazy-object-proxy-1.2.2.tar.gz

Component: packages: standard

Author: Erik Bray

Branch/Commit: u/embray/lazy_object_proxy @ 5702355

Issue created by migration from https://trac.sagemath.org/ticket/22792

[embray]

Description changed:

--- 
+++ 
@@ -2,6 +2,6 @@
 
 This could be used to replace code in `sage.misc.lazy_import`.  It's also a slightly more generic implementation of a lazy proxy (granted, the existing one in Sage could also be made more generic with only slight modifications).
 
-More details about how I intend to use this in a followup ticket.
+More details about how I intend to use are in #22793.
 
 **Upstream tarball:** https://pypi.python.org/packages/65/63/b6061968b0f3c7c52887456dfccbd07bec2303296911757d8c1cc228afe6/lazy-object-proxy-1.2.2.tar.gz

[jdemeyer]

comment:3

Don't forget to update build/pkgs/lazy_object_proxy/SPKG.txt

[jdemeyer]

comment:4

What's up with this, does it really require clang?

if [ "$UNAME" = "Darwin" ] && [ $MACOSX_VERSION -ge 16 ]; then
    echo "OS X 10.$[$MACOSX_VERSION-4] Building with clang."
    CC=clang
fi

[embray]

comment:5

Oops, no, I obviously just copied the package from psutil and didn't check closely enough. Very tired.